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Related papers: A Survey Length for AGN Variability Studies

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We present the results from the spectral analysis of more than 7,500 RXTE spectra of 10 AGN, which have been observed by RXTE regularly over a long period of time ~ 7-11 years. These observations most probably sample most of the flux and…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-02 M. A. Sobolewska , I. E. Papadakis

Continuous time random walks (CTRWs) are used in physics to model anomalous diffusion, by incorporating a random waiting time between particle jumps. In finance, the particle jumps are log-returns and the waiting times measure delay between…

Data Analysis, Statistics and Probability · Physics 2008-12-10 Mark M. Meerschaert , Enrico Scalas

This paper reviews the Stochastic Recurrent Neural Network (SRNN) as applied to the light curves of Active Galactic Nuclei by Sheng et al. (2022). Astronomical data have inherent limitations arising from telescope capabilities, cadence…

Instrumentation and Methods for Astrophysics · Physics 2023-03-24 Xinyue Sheng , Matt Nicholl , Nicholas Ross

We constrain the behavior of the radio luminosity function (RLF) of two classes of active galactic nuclei (AGN) namely AGN of low radio power (LRP) and BL Lac objects. The extrapolation of the observed steep RLFs to low power predicts a…

Astrophysics of Galaxies · Physics 2015-06-24 Alessandro Capetti , Claudia M. Raiteri

Continuum and emission-line variability of active galactic nuclei provides a powerful probe of microarcsecond scale structures in the central regions of these sources. In this contribution, we review basic concepts and methodologies used in…

Astrophysics · Physics 2016-11-03 Bradley M. Peterson

The long-term variability study over a range of black hole (BH) mass systems from the microquasars of stellar-mass black holes to the Active Galactic Nuclei (AGNs) of supermassive black holes, in $\gamma$-rays offers new insights into the…

High Energy Astrophysical Phenomena · Physics 2024-10-10 Ajay Sharma , Raj Prince , Debanjan Bose

This paper derives and analyzes continuous time random walk (CTRW) models in radial flow geometries for the quantification of non-local solute transport induced by heterogeneous flow distributions and by mobile-immobile mass transfer…

Fluid Dynamics · Physics 2016-11-28 Marco Dentz , Peter K. Kang , Tanguy le Borgne

This paper presents light curves and the first systematic characterization of variability of the 106 objects in the Fermi Large Area Telescope (LAT) Bright AGN Sample (LBAS). Weekly light curves obtained during the first 11 months of survey…

High Energy Astrophysical Phenomena · Physics 2015-05-18 A. A. Abdo

In our previous work, we applied the ICCF-Cut method to the continuum reverberation mapping (CRM) of six active galactic nuclei (AGNs) based on the published Swift data. Extending this work, we perform a systematic AGN CRM study utilizing…

Astrophysics of Galaxies · Physics 2025-11-11 Chi-Zhuo Wang , Xue-Bing Wu , Yuanzhe Jiang , Qinchun Ma , Huapeng Gu , Yuhan Wen

Aims: Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X-ray range above 20 keV. Methods: The first 9 months of the Swift/BAT all-sky survey…

We present a comprehensive study of five nearby active galaxies featuring large (tens of kpc) extended emission-line regions (EELRs). The study is based on large-format integral field spectroscopic observations conducted with the Multi Unit…

Astrophysics of Galaxies · Physics 2025-11-05 C. Finlez , E. Treister , F. Bauer , M. Koss , W. Keel , W. Maksym , L. Sartori , G. Venturi , C. Ricci , N. Nagar , C. Riesco , Y. Díaz , M. Parra

We study variability of active galactic nuclei (AGNs) by using the deep optical multiband photometry data obtained from the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP) survey in the COSMOS field. The images analyzed here were taken…

Astrophysics of Galaxies · Physics 2020-05-13 Yuki Kimura , Toru Yamada , Mitsuru Kokubo , Naoki Yasuda , Tomoki Morokuma , Tohru Nagao , Yoshiki Matsuoka

Changing-Look Active Galactic Nuclei (CLAGN) are characterised by extreme variations in line emission over short timescales, mostly affecting broad H$\beta$ lines. While a few hundred CLAGN are known, a complete sample of turn-on CLAGN is…

Astrophysics of Galaxies · Physics 2024-10-31 Neelesh Amrutha , Christian Wolf , Christopher A. Onken , Wei Jeat Hon , Samuel Lai , John L. Tonry , Rachel Webster

The local (z=0.0315) AGN Mrk 817, was monitored over more than 500 days with space-borne and ground-based instruments as part of a large international campaign AGN STORM 2. Here, we present a comprehensive analysis of the broad-band…

In recent years, graph neural networks (GNNs) have gained increasing popularity and have shown very promising results for data that are represented by graphs. The majority of GNN architectures are designed based on developing new…

Machine Learning · Statistics 2021-10-05 Anahita Iravanizad , Edgar Ivan Sanchez Medina , Martin Stoll

Winds launched at the scale of the accretion disc or dusty torus in Active Galactic Nuclei (AGN) are thought to drive energy-conserving outflows that shape galaxy evolution. The key signature of such outflows, the presence of a hot ($T…

Astrophysics of Galaxies · Physics 2026-02-06 Ivan Almeida , Tiago Costa , Chris M. Harrison , Samuel R. Ward

Gamma-ray bursts (GRB) are extremely energetic events and produce highly diverse light curves. Light curves are believed to be resulting from internal shocks reflecting the activities of the GRB central engine. Hence their temporal studies…

High Energy Astrophysical Phenomena · Physics 2013-07-30 P. N. Bhat

The Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) program monitors 849 active galactic nuclei (AGN) both spectroscopically and photometrically. The photometric observations used in this work span over four years and provide an…

We develop a robust technique to determine the minimum variability timescale for Gamma-ray Burst light curves, utilizing Haar wavelets. Our approach averages over the data for a given GRB, providing an aggregate measure of signal variation…

High Energy Astrophysical Phenomena · Physics 2015-06-19 V. Zach Golkhou , Nathaniel R. Butler

We consider activated random walk (ARW), an interacting particle system and prototypical model of self-organized criticality in a setting which combines mean-field behavior with the geometry of an arbitrary graph, which we call the village…

Probability · Mathematics 2026-05-11 Balázs Ráth , Jacob Richey , Miklós Salánki
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